Thought this might help someone...
This is my setup:
1 Bus Pirate
1 hacked Nokia FBUS cable with only RX, TX and GND
1st - BP is powering the JeeNode and AUX(BP) pin connected on RST(JN)
2nd - Nokia FBUS cable connected on RX,TX and GND (JN)
3rd - Configured Arduino IDE as told here on jeelabs
4th - Open terminal (used PuTTy) and activate AUX as HIGH
5th - Click UPLOAD on Arduino IDE and wait until code is compiled
6th - Quickly set AUX as LOW and wait.
Voilá, code uploaded :)